The invention concerns an arrangement for cooling a synthetic gas, generated in a gasification reactor, by means of a quenching cooler positioned below the outlet from the reactor and comprising a refrigerated inner jacket surrounded by a pressurization jacket and accommodating a water sump, with an intermediate section between the inner jacket and the outlet from the gasification reactor that is shorter in diameter than the inner jacket and longer in diameter than the outlet from the reactor.
The inner jacket of a known quenching cooler (DE-C 2 940 933) is refrigerated by surface irrigation. It is difficult to apply a film of water to the surface of the inner jacket because the water tends to evaporate on the hot surface and break up the film. The gas generated in the gasification reactor is conveyed through a water sump in the known quenching cooler to cool it, saturate it with water, and free it of liquid slag and fly ash. The drawback to this type of quench cooling is that the water in the sump also picks up the halogen constituents in the gas and is heated by it. The water must accordingly, once the solids have been removed, be subjected to further processing and cooling. there is also a risk of the gas entraining droplets of water with fine particles of dust suspended in them as it leaves the sump in the known quenching cooler. These particles of dust can cake together on the wall of the cooler and in the downstream pipelines and clog them up.
The object of the invention is to cool the synthetic gas in an arrangement of the known type in such a way that the water sump will remain free of halogen constituents and deposits of dust will be prevented.
This object is attained in accordance with the invention in an arrangement of the type initially described in that spray nozzles extend into the inner jacket and in that one or more gas-outlet connections extend through the inner jacket in a plane above the water sump. Evaporation cooling can be carried out in a space without differential pressure and opening into the inner jacket between the inner jacket and the pressurization jacket. Other practical embodiments of the invention will be discussed in connection with the description.
The amount of steam in the synthetic gas is controlled in this arrangement by spraying water into the current of gas and not by conveying it through a water sump. The surface temperature of the refrigerated inner jacket will in normal operation more or less equal the boiling point that corresponds to the gasification operating pressure. Since the surface temperature is accordingly high above the saturation point that corresponds to the steam pressure of the synthetic gas, it will never drop below the dew point at the inner jacket. The spray nozzles and the intermediate section between the reactor outlet and the inner jacket will keep the reactor outlet warm, preventing the outlet from clogging up with solidifying liquid slag.
Several embodiments of the invention are illustrated in the drawing and will now be described in detail.